Here's an interesting thought I had recently. Obviously, Nintendo and Microsoft would need to strike a deal in order for Banjo (a Microsoft-owned character) to appear in Super Smash Bros. Ultimate (a Nintendo-produced, published, and intellectual-property-owned game exclusively produced for the Nintendo Switch). It seems only fair to me that this deal involve a licensing rights arrangement to allow for an iconic Nintendo-owned character, preferably the main character of a famous and beloved Nintendo-owned IP, to appear in the roster of a triple-A Xbox One-exclusive title of a famous Microsoft IP in a substantial "special guest" role.
My query for the Banjo-roos is: which Nintendo character do you think would be most likely to be licensed out for a guest appearance in an Xbox One game in exchange for Banjo being licensed as a DLC character for Super Smash Bros. Ultimate, and which Xbox One title (specifically or in general) would be graced with a guest appearance from that Nintendo character? Try to make the trade as fair as possible, taking into account how much of a big name the Nintendo character is relative to Banjo (remember, the Banjo franchise is, sadly, not one of Microsoft's primary IPs) and how much of a grand phenomenon the Xbox franchise and game is relative to Super Smash Bros. Ultimate.
The best I can come up with is Samus making a guest appearance in the next Halo game. Halo is one of Microsoft's all-time biggest franchises; if Smash is the defining franchise for platform fighters, then Halo is, if not the defining franchise for modern first-person shooters, a very strong contender for the title. As for Samus, well, Metroid is fairly big, but it's certainly not one of Nintendo's top IPs, so Nintendo leasing Samus in exchange for Microsoft leasing Banjo feels like a relatively even trade IMO. Furthermore, a crossover between Halo and Metroid wouldn't feel substantially strange with respect to either franchise, considering that they both fit into the sci-fi genre story-wise and have a lot of similar backstory and environmental elements. But, anyways, what sort of licensing exchange do you guys think makes the most sense?